Attachment plug



ifratented yNove-22, i. j

, 1 fUNIT-ao:sriiresv This invention'relates particularly to a Vnew and improved lattachment plug fork electrical connections.

{'An object ofthefinventio'n f is to ,providefa' separableelectrical comiector wherein, both the plug `member and Abase 'member are `c yliridrica`l` in cross. section,` and the contacts or `terminals on the respeetive'members are arranged in spaced axial alignment, thus enabling yip hegparts.,to be engaged or disengaged more ``q1`1ickly`and with greater facility than in theicon'ventional type of attachment `plug which has apair of tonguelike terminals projecting Vtherefroli'i,in parallel relation.' `A further l vision of .an attachment of the character`de scribed wherein the. xed part of the,` plugfisQs'o constructedthatthe contact terminalsfof the movable part are `guided naturally, merelyby contact withthe contacts in the.xed'part'.of the plug, and"` wherein the connection" mayv be made without the aid of sight, and without the necessity of rotating or moving. a` pairof termi'- nals into engagement witha pairofsockets, as is the 'case with the"conventional typ`e"of 'ati tachment'plug. L i 5;"

`Other objects and' advantages arejto provide an attachment plug fcrelectrical connections that will Abesuperior inpoint ofsimplicitminexpensivenessof construction, positiveness of ope` general efficiency.A .y `In this specification and the annexed ldravv! ing,v the invention is illustrated in .the'fform` con- Y eration, and facility and, conveniencednuse. and

sidered to be the best, but it 1s to beiuncerstood that the inventionfis' not limited to "such form, because Vit may be embodiedin'other forms; .and it is also to be understoodthat in andby the claim following'the descriptiongit is desired to 4I) cover the inventioninwhatsoever form it may In `the accompanying drawing:

Fig. l representsaside'elevation of a separable attachment plug constructed in accordance with 45 my invention.

Fig. 2 is a section taken through Fig. 1. showing the base member in section and the plug member in elevation. Y

Fig. 3 is a cross section through the basemem- 50 ber and showing the axially` aligned contacts therein.

Fig. 4 is a view of the plug member partly in section, to show the construction thereof.

65 plug member.

object ,of the inventionfis';theprol Fig.' "6 is an enlarged cross ctioii taken through Fig. 4 ,lon the line Fig. 7` is'a Dlan'view cfa modified form of base member.

tjrn. detau .thctstrction Vi1 1usomted in the drawing ccnsistsj of a twopart "electrical conlnecto'r comprisiedfof the base or iixed'mernber generally designated byfthe numeral A; and the plug orrv movable Ymember ygenerally designated b'y the numeral B. "Ilie'basemember Afconsists o f a pressed metal shell'having athread 3 offconventional pitch rolled there on,`" tof fenablesaid c base tol be screwed jinto a conventional electric lentirely insulated from sa'id s'hell said contact 8 -having arivet 9" thereon whichextendsthrough layers of insulation I II o ithe'` endcf 'the `basev rnembenintoengagement with a buttonv II. The contact 8 iscirculnferentially dividedto `form in eiIect`,' an annular spring'nger socket, and the inner` diameter' of said .font'act'1 c is less 'than `the inner diameter of thatbf the contact 5, at the outer end Aoif' `sa .i`cl base;v` Both fof the annular contacts 5 and 8 are adaptedjto` expand or dilate when'the plug memberB is engaged therewith, andthereby" frictionallyengageuthe said plug member LI B .tol firmly resist disengagement.

' The plugmember B` consists" of a tube of insulating material I 2 having an internally ythreaded ring I3 orcontactingjmaterial at one end thereof, and 4acallar AI4 of like material,` `around theoutside thereof@ One side of the ring I3 vis cutaway asat 5,` to' permit thevend-of a wire I6` to be insertedtherethroughand tobe clamped against the outer end'of the ring I3 by a threaded screw I 1. The wire I6-is`preferably carried in an insulated mounting I8, and connects to a source of electrical energy. The other wire I9, which is carried in the mounting I8 extends through an opening 20 in the side of the insulated shell I2. Theend of the wire is projected through the opening 20 and laid against the outside of the shell, and thereafter, a terminal or ring 2| of conducting material, is moved axially on the shell I2 to clamp the end of ythe'wire I9 tightly against the shell, to establish an electrical contact with said ringZI. A bayonet joint opening 22 is provided in the shell I2 adjacent the opening 20, and the ring 2'Ihis provided with a finger 23 thereon, which moves in said bayonet slot 22 to guide the said ring on the shell l2 when engaging and disengaging it from the exposed end of the wire I9. The outer diameter of the ring 2| is greater than that of the ring I4 at the extreme end of the plug B, and likewise is slightly greater than the internal diameter of the spring contacts 5. i The external diameter othe ring I4 on the plug B is likewise slightly greater than thatof the socket contact 8, altho it ls appreciably less than the internal diameter of the spring fingers 5. The width of the terminal ring Il is likewise less than the distance or space between the contacts 5 and 8 to prevent the possibility of said ring Il shortcircuiting between the contacts 5 and 8. With our type of plug, the operator need only insert the same completely intothe base member, and an electrical connection is made which will resist disconnection to a greater extent thanthe ordinaryI separable plug.

The ordinary separable plug/,which is conventionally used, consists of a base member formed of insulating material, and from a face of which a. pair ofkterminal prongs extend, each prong being connected by a Wire to` an element to be energized by electricity.'` The base member into which the prongs on the plug are adapted to be positioned, is'provlded with a. pair of holes there'- in, and a pair of contact members are positioned inthe holes to receive the plug prongs. tacts inthe base are suitably connected to exlternal means on the base to make contact with a source of electrical energy. i

In the conventional plug, if abused, or dragged around on the floor, or stepped upon, the prongs thereof become loose or break so that either a short-circuit is formed, or the'plug becomes useless. Once the prongs on the plug become loose, they will not hold their'po'sition in the base, and will not hold anappreciable length of extension cord in connection with arsource of electrical energy. The conventional plug is further to be criticized in that it is extremely diicult to enter vthe prongs into the sockets of the base', if lighting conditions'are bad, or if the base is not'in an accessible position.

With our assembly, there is butone hole in the base into which the plug may be inserted, and the user of the plug can make the connection in much quicker time and with greater facility, even where the lighting conditions may be bad, or Where the base oi` the Aplug may be in a'slightly inaccessible position. Our plug is made of unbreakable material and can be dropped,- abused, or steppedupon to a great extent, without rendering it inoperative. The tension of the spring contacts in our base when engaged with the plus', requires a pulling force to disengage the same manytimes greater than the force necessary to pullthe conventional plug The conout of the base. Furthermore, with our device, the plug can be pulled from the socket by pressure exerted on the cord attached to the plug, and no damage will be caused any part of the cord connection. The plug is likewise of a. diameter which is very small and compact, and it is not clumsy 'or objectionable in size.

The base member shown in Figs. 1, 2 and 3, is provided with a. screw thread thereon, for attachment to a conventional type of screw threaded socket.

In Fig. '7 I have shown a modiiied form of base member, which is conventionally referred to as a door or Wall plug. In this type of device, the base member is permanently secured in the' wall or floor, and it is always in position to receive the plug. l

In either the preferred or modied form of the device, the plug and base member are so constructed that only one electrical connection can be made vat a time. VWherejthe'type of base shown in the modified form in Fig. 7, would be providedwith two plug receiving receptacles, thenvof course, two electrical connections c'ould be established. It is one of the objects of our invention that the plug land base be so constructed that only one 'connection'can be made, and

to eliminate the possibility of a multiple outletv plug beingv connectedinto the base, preventing the overloading of electrical energy being taken from the single outlet` as is often the case'with theconventional type of plug and base.

Having thus described this invention, what we claim and vdesire to secure by Letters Patent is: A base for an electrical connector, comprising a metal shell, said shell being of substantially cup-like form but having its closed end formed to provide an aperture therethrough,'the open end of said shell being slotted longitudinally to provide aplurality of spaced longitudinally extending prongs extending circumferentially around said open end, a sleeve of insulation material around the interior of, and an insulation disc at the interior bottom of said shell, a disc of insulating material overlying the bottom of said shell on the outside thereof, a yieldable cuplike contact in the bottom of said shell on said insulation disc, a contact on the outside of said insulating disc, a connection between said contact (and saidl cup-like contact, said connection extending through theinterior and exterior insulating discs and the aperture in the closed end of said shell and spaced from the side edges of the latter, said connection comprising means for uniting said contact, discs, v,and shell, said prongs being bent inwardly over the upper edges of said insulation sleeve 1n substantial parallelism with the sides thereof to provide an annular spring contact spaced from said cup-like contact, and a cylindrical insulating member surrounding the upper portion ci' said shell.

vMORRIS W. BERGER.

PETER WEIN'BERG. 

